The sharpness is impressive for a UST projector. The color is definitely "respectable" but if you need really accurate color, say for viewing videos or viewing serious photography, you can find better color out there. For the typical business, school or government application though the color should be just fine. In fact I'd say its better than most of the DLP competition.
The feature set is very strong. You can ding it for not having a full set of interactive features including pens or annotating with your fingers on the screen. You'll have to decide how much interactivity you want and will pay for. As an example, Epson makes some UST's with and without full interactivity. The Epson with a feature set similar to the Casio, is several hundred less, but uses lamps that will need replacing. Their full blown interactive is about $400 more than the Casio, and still uses lamps, not a long life engine.
3D capability is limited in terms of formats supported, but networking support, by comparison, is especially strong.
All considered the Casio XJ-UT310WN has to be considered a cut above the average ultra short throw projector. It's not inexpensive, but it is, price wise, competitive!
Casio is the #1 player in terms of solid state light engines. With the UT310WN, they currently "own" the ultra short throw field, in terms of those with solid state light engines. They aren't the only player - Panasonic, and also, I believe, Sony, now have ultra short throw optional lenses for their laser projectors, but, considering those lenses alone cost a lot more than this projector, we're talking upward of $6000 - 3x the price.
I am pretty impressed. I just wish our photos better represented the color quality that the projector puts on the screen. Good job!